Methods for inhibiting the progression of neurodegenerative diseases

ABSTRACT

Disclosed are methods for inhibiting the progression of neurodegenerative disease. The methods include administering to a patient suffering from such a disease a composition comprising either deuterated arachidonic acid or an ester thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of and claims the benefitunder 35 U.S.C. § 120 of U.S. patent application Ser. No. 17/391,909,filed Aug. 2, 2021, which is a continuation-in-part of U.S. patentapplication Ser. No. 17/169,271, filed on Feb. 5, 2021, each of which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

Disclosed are methods for inhibiting the progression ofneurodegenerative diseases in humans. The methods use a specific dosingregimen to treat patients suffering from a neurodegenerative diseasetreatable with a deuterated arachidonic acid or a prodrug thereof. Inparticular, the dosing regimen provides for rapid onset to a therapeuticconcentration in vivo of deuterated arachidonic acid at a level wherethe progression of the disease is markedly reduced.

BACKGROUND

There are a number of debilitating neurodegenerative diseases in humanswhich, despite the best efforts of researchers, remain incurable andoften fatal. As such, the best the attending clinician can do is to slowthe progression of the disease and, where possible, maintain ameaningful quality of life for the patient for as long as possible.Examples of such neurodegenerative diseases include the following:

-   -   amyotrophic lateral sclerosis (ALS) which is a late-onset,        progressive neurological disease with its corresponding        pathological hallmarks including progressive muscle weakness,        muscle atrophy and spasticity all of which reflect the        degeneration and death of upper and/or lower motor neurons. Once        diagnosed, most patients undergo a rapid rate of disease        progression terminating in death typically within 3 to 4 years        with some patients succumbing even earlier;    -   tauopathy is a subgroup of Lewy body diseases or proteinopathies        and comprises neurodegenerative conditions involving the        aggregation of tau protein into insoluble tangles. These        aggregates/tangles form from hyperphosphorylation of tau protein        in the human brain. Specific conditions related to tauopathy        include, but are not limited to, argyrophilic grain disease        (AGD), chronic traumatic encephalopathy (CTE), corticobasal        degeneration (CBD), frontotemporal dementia and parkinsonism        linked to chromosome 17 (FTDP-17), ganglioglioma, gangliocytoma,        lipofuscinosis, lytico-bodig disease, meningioangiomatosis,        pantothenate kinase-associated neurodegeneration (PKAN), Pick's        disease, postencephalitic parkinsonism, primary age-related        tauopathy (PART), Steele-Richardson-Olszewski syndrome (SROS),        and subacute sclerosing panencephalitis (SSPE). Wang et al.,        Nature Rev. Neurosci. 2016; 17:5 and Arendt et al., Brain Res.        Bulletin 2016; 126:238. Tauopathies often overlap with        synucleinopathies.    -   Steele-Richardson-Olszewski syndrome or progressive supranuclear        palsy (PSP) is one example of a neurodegenerative disease        mediated at least in part by tauopathy and involves the gradual        deterioration and death of specific volumes of the brain. The        condition leads to symptoms including loss of balance, slowing        of movement, difficulty moving the eyes, and dementia. A variant        in the gene for tau protein called the H1 haplotype, located on        chromosome 17, has been linked to PSP. Besides tauopathy,        mitochondrial dysfunction seems to be a factor involved in PSP.        Especially, mitochondrial complex I inhibitors are implicated in        PSP-like brain injuries;    -   Friedreich's ataxia is an autosomal-recessive genetic disease        that causes difficulty walking, a loss of sensation in the arms        and legs, and impaired speech that worsens over time. The        pathology of this neurodegenerative disease involves        degeneration of nerve tissue in the spinal cord;    -   Huntington's disease is a fatal genetic disorder that causes the        progressive breakdown of nerve cells in the brain;    -   Corticobasal disorder (CBD) is a rare neurodegenerative disease        characterized by    -   gradual worsening problems with movement, speech, memory and        swallowing. It's often also called corticobasal syndrome (CBS).        CBD is caused by increasing numbers of brain cells becoming        damaged or dying over time;    -   Frontotemporal dementia (FTD) is a neurodegenerative disease and        a common cause of dementia. It is characterized by a group of        disorders that occur when nerve cells in the frontal temporal        lobes of the brain are lost thereby causing the lobes to shrink.        FTD can affect behavior, personality, language, and movement;    -   Nonfluent variant primary progressive aphasia (nfvPPA) occurs as        a result of a buildup of one of two proteins, either tau or        TPD-43, usually in the front left part of the brain. That part        of the brain controls speech and language. As more of the        protein builds up in those brain cells, the cells lose their        ability to function and eventually die. As more cells die, the        affected portion of the brain shrinks; and    -   late onset Tay-Sachs is a very rare genetic neurodegenerative        disease in which fatty compounds, called gangliosides, do not        break down fully because the body produces too little of the        enzyme hexosaminidase A (or hex A). Over time, gangliosides        build up in the brain and damage brain nerve cells. This affects        a person's mental functioning.

There remains a need for treatments for these and otherneurodegenerative diseases.

SUMMARY

In one embodiment, methods are disclosed that significantly attenuatethe progression of neurodegenerative diseases treatable byadministration of deuterated arachidonic acid or an ester thereof. Suchadministration is delivered with a dosing regimen that comprises both aloading regimen and a maintenance regimen. The loading regimen ensuresthat there is a rapid onset to therapeutic levels of the deuteratedarachidonic acid in vivo to attenuate disease progression. This resultsin the retention of more functionality in the patient as compared todosing regimens that require longer periods of time to achievetherapeutic levels. The maintenance dose ensures that the therapeuticlevels of the deuterated arachidonic acid are maintained in the patientduring therapy.

In one embodiment, the deuterated arachidonic acid or ester thereof hasone or more deuterium atoms at the bis-allylic sites. In one embodiment,the deuterated arachidonic acid or ester is 13,13-D2-arachidonic acid oran ester thereof, 10,10,13,13-D4-arachidonic acid or an ester thereof,or 7,7,10,10,13,13-D2-arachidonic acid or an ester thereof. In anotherembodiment, there is provided a composition of deuterated arachidonicacid or ester thereof which composition comprises on average at leastabout 80% of the hydrogen atoms at the bis-allylic sites replaced bydeuterium atoms. In one embodiment, the deuterated arachidonic acid orester thereof comprises on average at least about 80% of the hydrogenatoms at the bis-allylic sites replaced by deuterium atoms and no morethan about 35% on average of the hydrogen atoms at the mono-allylicsites replaced by deuterium atoms.

In one embodiment, the deuterated arachidonic acid or ester thereof is13,13-D2-arachidonic acid or an ester thereof.

In one embodiment, the deuterated arachidonic acid or ester thereof is10,10,13,13-D4-arachidonic acid or an ester thereof.

In one embodiment, the deuterated arachidonic acid or ester thereof is7,7,10,10,13,13-D6-arachidonic acid or an ester thereof

Without being limited by theory, once administered, deuteratedarachidonic acid is systemically absorbed and incorporated into cells,such as the cell membrane and the mitochondria. In neurons, thedeuterated arachidonic acid stabilizes the cell membrane againstoxidative damage caused by reactive oxygen species. This, in turn, stopsthe cascade of lipid peroxidation, thereby minimizing damage to motorneurons where the deuterated arachidonic acid is incorporated. Whenconcentrations of deuterated arachidonic acid reach a therapeutic levelin the motor neurons, the disease progression of neurodegenerativediseases is significantly attenuated.

The methods described herein provide for rapid onset of a therapeuticconcentration of deuterated arachidonic acid in vivo so as to minimizeunnecessary loss of functionality in the treated patients suffering froma neurodegenerative disease. In one embodiment, there is provided amethod for reducing disease progression of a neurodegenerative diseasein an adult patient treatable with deuterated arachidonic acid whileproviding for rapid onset of therapy, the method comprising periodicallyadministering deuterated arachidonic acid or an ester thereof to thepatient with a dosing regimen that comprises a primer dose and amaintenance dose.

In an embodiment, the primer dose comprises periodic administration ofdeuterated arachidonic acid or an ester thereof. In an embodiment, theprimer dose comprises at least about 10 milligrams of deuteratedarachidonic acid or an ester thereof per day. In an embodiment, theprimer dose comprises from about 50 milligrams to about 2 grams ofdeuterated arachidonic acid or an ester thereof per day. In anembodiment, the primer dose comprises from about 0.10 grams to about 1gram. In an embodiment, the primer dose is continued for about 15 toabout 50 days or from about 30 days to about 45 days, e.g., to rapidlyachieve a therapeutic concentration of deuterated arachidonic acid invivo, thereby reducing the rate of disease progression.

In an embodiment, after completion of the primer dose, the maintenancedose is periodically administered. In an embodiment, no more than about65% of the loading dose of the deuterated arachidonic acid or an esterthereof per day is administered as a maintenance dose. In an embodiment,the maintenance dose is utilized to ensure that the therapeuticconcentration of deuterated arachidonic acid is maintained in vivo suchthat a reduced rate of disease progression is maintained.

In an embodiment, the reduced rate of disease progression is evaluatedwhen compared to the rate of disease progression measured prior toinitiation of said method. In an embodiment, each of saidneurodegenerative diseases is mediated at least in part by lipidperoxidation of polyunsaturated fatty acids in neurons of the patientsuffering from said neurodegenerative disease.

In one embodiment, said neurodegenerative disease is amyotrophic lateralsclerosis (ALS), Huntington's Disease, progressive supernuclear palsy(PSP), Friedreich's ataxia, APO-e4 Alzheimer's Disease, corticobasaldisorder (CBD), frontotemporal dementia (FTD), nonfluent variant primaryprogressive aphasia (nfvPPA), other tauopathies, or late onsetTay-Sachs.

In one embodiment, said periodic administration of the loading dosecomprises administration of from about 0.05 grams to about 2 grams ofdeuterated arachidonic acid or an ester thereof per day. In embodiments,the loading dose is administered for at least 5 days per week, andpreferably 7 days a week.

In one embodiment, the periodic administration of the maintenance doseof deuterated arachidonic acid or an ester thereof per day comprises nomore than 55% of the loading dose. In embodiments, the maintenance doseis administered per day, or at least 5 days per week, or at least onceper week, or at least once per month. In another embodiment, themaintenance dose comprises no more than 35% of the loading dose which isadministered at least once a month.

In one embodiment, the periodic administration of the maintenance doseis calibrated to be an amount of deuterated arachidonic acid or an esterthereof sufficient to replace the amount of deuterated arachidonic acideliminated from the body.

In one embodiment, the percent reduction in the rate of diseaseprogression is determined by:

measuring a natural rate of disease progression in a patient or anaverage natural rate of disease progression in a cohort of patientsprior to initiation of therapy per the methods described herein;

measuring the rate of disease progression in said patient or cohort ofpatients during a period of compliance with the periodic administrationof both the loading dose and the maintenance dose; and

after said period of compliance from the start of therapy, optionallyannualizing the progression rate during the natural history and theprogression rate during therapy, calculating the difference between thenatural rate and the rate during the period of compliance, dividing thedifference by the rate of disease progression during the natural historyof the patient, and multiplying by 100.

In one embodiment, the set period of time is between about 1 month andabout 24 months, for example about 3 months, about 6 months or about 12months, or about 18 months or about 24 months. In an embodiment, the setperiod of time is at least 3 months.

In one embodiment, the methods described herein further compriserestricting the patient's consumption of excessive dietarypolyunsaturated fatty acids during administration of said primer andsaid maintenance doses.

In one embodiment, there is provided a kit of parts comprising a set ofcapsules, each capsule comprising a partial loading dose of deuteratedarachidonic acid or an ester thereof, such that two or more of saidcapsules comprise a complete loading dose per day.

In one embodiment, there is provided a kit of parts comprising a set ofcapsules, each capsule comprising a partial loading dose of deuteratedarachidonic acid or an ester thereof, such that no more than four ofsaid capsules comprise a complete loading dose per day.

In one embodiment, there is provided a kit of parts comprising a set ofcapsules, each capsule comprising a partial maintenance dose ofdeuterated arachidonic acid or an ester thereof, such that two or moreof said capsules comprise a complete maintenance dose per day.

In one embodiment, there is provided a kit of parts comprising a set ofcapsules, each capsule comprising a partial maintenance dose ofdeuterated arachidonic acid or an ester thereof such that one or two ofsaid capsules comprise a complete maintenance dose per day.

In one embodiment, the percent reduction in the rate of diseaseprogression from that occurring during the natural history of thepatient and after start of therapy is at least 25%, at least 30%,preferably at least 40%, more preferably at least 65% and mostpreferably greater than 70% or 80% after 3 or 6 months. Accordingly, insome embodiments, methods disclosed herein provide for determining apercent reduction in the rate of disease progression by (i) determininga natural rate of disease progression in a patient or an average naturalrate of disease progression in a cohort of patients; (ii) determiningthe rate of disease progression in the patient or cohort of patientsduring a period of compliance with administration of deuteratedarachidonic acid, an ester thereof, or a prodrug thereof; (iii)measuring the difference between the natural rate of disease progressionand the rate during the period of compliance, (iv) optionallyannualizing the progression rate during the natural history and theprogression rate during therapy; (v) dividing the difference by thenatural rate of disease progression and (vi) multiplying by 100.

In one embodiment, whether a therapeutic concentration of deuteratedarachidonic acid has been reached in neurons is measured using areporter cell. In an embodiment, the reporter cells are red blood cells.In the case of red blood cells, a concentration of 13,13-D2-arachidonicacid of at least about 3% based on the total number of arachidonic acid,including deuterated arachidonic acid, contained in the red blood cellshas been found to correlate with therapeutic results. See, e.g., U.S.Provisional Patent Application No. 63/177,794, filed Apr. 21, 2021,which is incorporated by reference in its entirety.

In one embodiment, the patients are placed on a diet that restrictsintake of excessive amounts of linoleic acid. This is because linoleicacid competes with arachidonic acid for incorporation into membranes andbioactive pools. Excess linoleic acid will result in diminished amountsof arachidonic acid in these pools. Generally, dietary components thatcontribute to excessive amounts of PUFA consumed are restrictedincluding, for example, fish oil pills, products that contain highlevels of PUFAs, such as salmon; patients on conventional feeding tubesmay also have excessive PUFA intake. In a preferred embodiment, themethods described herein include both the dosing regimen described aboveas well as placing the patients on a restrictive diet that avoidsexcessive ingestion of PUFA components and especially excessive linoleicacid.

In one embodiment, there is provided a method for reducing the rate ofdisease progression in a patient suffering from a neurodegenerativedisease treatable with deuterated arachidonic acid, which methodcomprises administering deuterated arachidonic acid or an ester thereofto the patient with a dosing regimen that comprises a primer dosing anda maintenance dosing schedule which comprise:

a) said first dosing component comprises administering to said patient aprimer dose of deuterated arachidonic acid or an ester thereof in anamount and for a period of time sufficient to allow for reduction in therate of disease progression within no more than about 45 days from startof dosing;

b) subsequently following said primer dose, initiating a maintenancedose to said patient, said maintenance dose comprises an amount ofdeuterated arachidonic acid or an ester thereof in an amount sufficientto maintain the concentration of deuterated arachidonic acid in themotor neurons, wherein the amount of deuterated arachidonic acid orester thereof administered in said maintenance dose is less than theamount administered in said primer dose; and optionally:

c) monitoring the concentration of deuterated arachidonic acid in thepatient to ensure that the patient is maintaining a therapeuticconcentration; and

d) increasing the dosing of deuterated arachidonic acid or an esterthereof when said concentration is deemed to be less than a therapeuticamount.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the percent of 13,13-D2-Arachidonic Acid inred blood cells (RBC) and cerebral spinal fluid (CSF) at the indicatedtime points after start of treatment with 11,11-D2-Linoleic Acid in anadult patient.

FIG. 2 is a graph showing the percent of 13,13-D2-Arachidonic Acid inred blood cells (RBC) and cerebral spinal fluid (CSF) at the indicatedtime points after start of treatment with 11,11-D2-Linoleic Acid injuvenile patients.

DETAILED DESCRIPTION

This disclosure is directed to methods for treating neurodegenerativediseases to significantly slow the rate of disease progression in apatient. In one embodiment, the methods of this disclosure include adosing regimen that is sufficient to provide a therapeutic level ofdeuterated arachidonic acid in the motor neurons. In another embodiment,the methods described herein comprise a daily or periodic primer orloading dose that accelerates delivery of deuterated arachidonic acid tothe diseased neurons of the patient. This primer dose is continued for asufficient period of time to achieve a therapeutic concentration of adeuterated arachidonic acid in vivo. At that point, a daily or periodicmaintenance dose is employed to maintain the therapeutic concentrationof the deuterated arachidonic acid.

Prior to discussing this invention in more detail, the following termswill first be defined. Terms that are not defined are given theirdefinition in context or are given their medically acceptabledefinition.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

As used herein, the term “optional” or “optionally” means that thesubsequently described event or circumstance can or cannot occur, andthat the description includes instances where the event or circumstanceoccurs and instances where it does not.

As used herein, the term “about” when used before a numericaldesignation, e.g., temperature, time, amount, concentration, and suchother, including a range, indicates approximations which may vary by (+)or (−) 15%, 10%, 5%, 1%, or any subrange or subvalue there between.Preferably, the term “about” when used with regard to a dose amountmeans that the dose may vary by +/−10%.

As used herein, the term “comprising” or “comprises” is intended to meanthat the compositions and methods include the recited elements, but notexcluding others.

As used herein, the term “consisting essentially of” when used to definecompositions and methods, shall mean excluding other elements of anyessential significance to the combination for the stated purpose. Thus,a composition consisting essentially of the elements as defined hereinwould not exclude other materials or steps that do not materially affectthe basic and novel characteristic(s) of the claimed invention.

As used herein, the term “consisting of” shall mean excluding more thantrace elements of other ingredients and substantial method steps.Embodiments defined by each of these transition terms are within thescope of this invention.

As used herein, arachidonic acid has the numbering system as describedbelow:

where each of positions 7, 10 and 13 are bis-allylic positions withinthe structure.

As used herein and unless the context dictates otherwise, the term“deuterated arachidonic acid or an ester thereof” refers to7-D1-arachidonic acid or an ester thereof; 10-D1-arachidonic acid or anester thereof; 13-D1-arachidonic acid or an ester thereof;7,10-D2-arachidonic acid or an ester thereof; 7,13-D2-arachidonic acidor an ester thereof; 10,13-D2-arachidonic acid or an ester thereof;7,7-D2-arachidonic acid or an ester thereof; 10,10-D2-arachidonic acidor an ester thereof; 13,13-D2-arachidonic acid or an ester thereof;7,10,13-D3-arachidonic acid or an ester thereof; 7,7,10-D3-arachidonicacid or an ester thereof; 7,10,10-D3-arachidonic acid or an esterthereof; 7,13,13-D3-arachidonic acid or an ester thereof;10,10,13-D3-arachidonic acid or an ester thereof;10,13,13-D3-arachidonic acid or an ester thereof;7,7,10,13-D4-arachidonic acid or an ester thereof;7,7,10,10-D4-arachidonic acid or an ester thereof;7,10,10,13-D4-arachidonic acid or an ester thereof;7,10,13,13-D4-arachidonic acid or an ester thereof;7,7,13,13-D4-arachidonic acid or an ester thereof;10,10,13,13-D4-arachidonic acid or an ester thereof;7,7,10,10,13-D5-arachidonic acid or an ester thereof;7,7,10,13,13-D5-arachidonic acid or an ester thereof;7,10,10,13,13-D5-arachidonic acid or ester thereof;7,7,10,10,13,13-D6-arachidonic acid or ester thereof; or mixtures of anytwo or more.

Preferred D2-arachidonic acids include 7,7-D2-arachidonic acid or estersthereof; 10,10-D2-arachidonic acid or esters thereof; and13,13-D2-arachidonic acid or esters thereof.

Preferred D4-arachidonic acids or esters thereof include7,7,10,10-D4-arachidonic acid or esters thereof;7,7,13,13-D4-arachidonic acid or esters thereof; and10,10,13,13-D4-arachidonic acid or esters thereof. In one embodiment,10,10,13,13-D4-arachidonic acid can be biosynthesized from8,8,11,11-D4-gamma linolenic acid or from 10,10,13,13-D6-d-homa-gammalinolenic acid. The bioconversion of both of these PUFAs results in10,10,13,13-D4-arachidonic acid. Both the 8,8,11,11-D4-gamma linolenicacid or the 10,10,13,13-D6-d-homa-gamma linolenic acid (or esters ofeither) can be prepared by ruthenium catalysis as described belowprovided that such will result in at least 80% deuteration of theirbis-allylic positions as well as nominal amounts of deuteration at oneor both of the mono-allylic positions (e.g., less than about 25%).

Preferred D6-arachidonic acid includes 7,7,10,10,13,13-D6-arachidonicacid or esters thereof including compositions of deuterated arachidonicacid or ester thereof that comprises, on average, at least about 80% ofthe hydrogen atoms at each of the bis-allylic sites having been replacedby deuterium atoms and, on average, no more than about 35% of thehydrogen atoms at the mono-allylic sites having been replaced bydeuterium atoms. For example, in the case of 80% deuteration of the 3bis-allylic sites and 35% deuteration of the mono-allylic sites, thetotal amount of deuterium is (6×0.8)+(4×0.35)=6.2 exclusive of thenaturally occurring amount of deuterium in each of the remainingmethylene and methyl groups within the structure.

As used herein and unless the context dictates otherwise, the term “anester thereof” refers to a C₁-C₆ alkyl esters, glycerol esters(including monoglycerides, diglycerides and triglycerides), sucroseesters, phosphate esters, and the like. The particular ester groupemployed is not critical provided that the ester is pharmaceuticallyacceptable (non-toxic and biocompatible). In one embodiment, the esteris a C₁-C₆ alkyl ester which is preferably an ethyl ester.

As used herein, the term “phospholipid” refers to any and allphospholipids that are components of the cell membrane. Included withinthis term are phosphatidylcholine, phosphatidylethanolamine,phosphatidylserine, and sphingomyelin. In the motor neurons, the cellmembrane is enriched in phospholipids comprising arachidonic acid.

As used herein, the term “pathology of a disease” refers to the cause,development, structural/functional changes, and natural historyassociated with that disease. The term “natural history” means theprogression of the disease in the absence of treatment per the methodsdescribed herein.

As used herein, the term “reduced rate of disease progression” meansthat the rate of disease progression is attenuated after initiation oftreatment as compared to the patient's natural history. In one case, therate of reduction in disease progression using the methods describedherein results in a percentage reduction of at least 25% lower or atleast 30% lower at a time point, e.g., 1 month to 24 months, e.g., 3 or6 months, after initiation of therapy when compared to the naturalhistory of the patient.

The term “therapeutic concentration” means a concentration of adeuterated arachidonic acid that reduces the rate of disease progressionby at least 25% or at least 30%. Since measuring the concentration of adeuterated arachidonic acid in the motor neurons or in the spinal fluidof a patient is either not feasible or optimal, the therapeuticconcentration is based on the concentration of deuterated arachidonicacid found in red blood cells as provided in the Examples below.Accordingly, any reference made herein to a therapeutic concentration ofdeuterated arachidonic acid is made by evaluating its concentration inred blood cells.

Alternatively, the reduction in the rate of disease progression isconfirmed by a reduction in the downward slope (flattening the curve) ofa patient's relative muscle functionality during therapy as compared tothe downward slope found in the patient's natural history. Typically,the differential between the downward slope measured prior to treatmentand the slope measured after at least 90 days from initiation oftreatment has a flattening level of at least about 30%. So, a change of7.5 degrees (e.g., a downward slope of 25 degrees during the naturalhistory that is reduced to a downward slope of 17.5 degrees provides fora 40% decrease in the slope). In any case, the reduction in downwardslope evidence that the patient has a reduced rate of diseaseprogression due to the therapy.

As used herein, the term “patient” refers to a human patient or a cohortof human patients suffering from a neurodegenerative disease treatableby administration of deuterated arachidonic acid or an ester thereof.The term “adult patient” refers to a subject over 18 years of age andsuffering from a neurodegenerative disease treatable by administrationof deuterated arachidonic acid or an ester thereof.

As used herein, the term “loading or primer amount” refers to an amountof a deuterated arachidonic acid or an ester thereof that is sufficientto provide for a reduced rate of disease progression within at leastabout 45 days after initiation of administration and preferably within30 days. The amount so employed is loaded to accelerate the period oftime to reduce the rate of disease progression within this time period.When less than a loading amount is used, it is understood that such canstill provide for therapeutic results but the time period between startof therapy and when therapeutic results are achieved will be longer and,likely, will not achieve the same level of reduction in diseaseprogression. Moreover, given the progressive nature of theseneurodegenerative diseases, the use of the dosing regimens describedherein will minimize the time necessary to achieve the desired reductionin the rate of disease progression thereby retaining as much of thepatient's remaining muscle functionality while limiting further loss offunctionality.

The methods described herein are based on the discovery that the primerdoses of deuterated arachidonic acid or an ester thereof employed todate are well tolerated by patients and provide for rapid onset of asufficient in vivo concentration of deuterated arachidonic acid toprovide for a reduced and stabilized rate of disease progression.

As used herein, the term “maintenance dose” refers to a dose ofdeuterated arachidonic acid or an ester thereof that is less than theprimer dose and is sufficient to maintain a therapeutic concentration ofdeuterated arachidonic acid in the cell membrane of red blood cells and,hence, in the cell membrane of motor neurons, so as to retain a reducedrate of disease progression. In one embodiment, the deuteratedarachidonic acid or ester thereof is the same compound as used in theloading dose and the maintenance dose.

As used herein, the term “periodic dosing” refers to a dosing schedulethat substantially comports to the dosing described herein. Stateddifferently, periodic dosing includes a patient who is compliant atleast 75 percent of the time over a 30-day period and preferably atleast 80% compliant with the dosing regimen described herein. Inembodiments, the dosing schedule contains a designed pause in dosing.For example, a dosing schedule that provides dosing 6 days a week is oneform of periodic dosing. Another example is allowing the patient topause administration for from about 3 or 7 or more days (e.g., due topersonal reasons) provided that the patient is otherwise at least 75percent compliant. Also, for patients who transition from the loadingdose to the maintenance dose, compliance is ascertained by both theloading dose and the maintenance dose.

The term “cohort” refers to a group of at least 2 patients whose resultsare to be averaged.

As used herein, the term “pharmaceutically acceptable salts” ofcompounds disclosed herein are within the scope of the methods describedherein and include acid or base addition salts which retain the desiredpharmacological activity and is not biologically undesirable (e.g., thesalt is not unduly toxic, allergenic, or irritating, and isbioavailable). When the compound has a basic group, such as, forexample, an amino group, pharmaceutically acceptable salts can be formedwith inorganic acids (such as hydrochloric acid, hydroboric acid, nitricacid, sulfuric acid, and phosphoric acid), organic acids (e.g.,alginate, formic acid, acetic acid, benzoic acid, gluconic acid, fumaricacid, oxalic acid, tartaric acid, lactic acid, maleic acid, citric acid,succinic acid, malic acid, methanesulfonic acid, benzenesulfonic acid,naphthalene sulfonic acid, and p-toluenesulfonic acid) or acidic aminoacids (such as aspartic acid and glutamic acid). When the compound hasan acidic group, such as for example, a carboxylic acid group, it canform salts with metals, such as alkali and earth alkali metals (e.g.,Na⁺, Li⁺, K⁺, Ca²⁺, Mg²⁺, Zn²⁺), ammonia or organic amines (e.g.,dicyclohexylamine, trimethylamine, trimethylamine, pyridine, picoline,ethanolamine, diethanolamine, triethanolamine) or basic amino acids(e.g., arginine, lysine, and ornithine). Such salts can be prepared insitu during isolation and purification of the compounds or by separatelyreacting the purified compound in its free base or free acid form with asuitable acid or base, respectively, and isolating the salt thus formed.

The phrase “excessive amounts of linoleic acid”, or “excessive linoleicacid intake,” and the like refer to the total intake of linoleic acid inamounts that would reduce the amount of arachidonic acid, includingdeuterated arachidonic acid, incorporated into the tissue and bioactivepools of the patient.

Pathology

The underlying pathology of each of the neurodegenerative diseases isindependent of the underlying etiology of the disease. That is to saythat whatever divergent conditions trigger each of theseneurodegenerative diseases (the etiology), once triggered the pathologyof these diseases involves lipid peroxidation of arachidonic acid inneurons. It should be noted that while deuterated arachidonic acidinhibits lipid peroxidation, there are a number of neurodegenerativediseases that are not treatable by the administration of deuteratedarachidonic acid or an ester thereof. Hence, only neurodegenerativediseases that respond to the administration of deuterated arachidonicacid are suitable for use in the methods described herein. These includeamyotrophic lateral sclerosis (ALS), tauopathy (including progressivesupernuclear palsy—PSP), Friedrich's ataxia, Huntington's Disease,Corticobasal disorder (CBD), Frontotemporal dementia (FTD), Nonfluentvariant primary progressive aphasia (nfvPPA), APO-e4 Alzheimer'sDisease, and late onset Tay-Sachs.

Neurodegenerative diseases that to date have not been shown to respondto treatment with deuterated arachidonic acid or an ester thereofinclude GPX4 Deficiency, Neuroserpinosis, and ACOX1-GOF.

As to the specifics, the discovery of several aldehydes that easilyreacted with sulfhydryl groups, resulting in the inhibition of vitalmetabolic processes, led to the association of polyunsaturated fattyacid peroxidation as a component of the pathology of many ofneurodegenerative diseases (Schauenstein, E.; Esterbauer, H. Formationand properties of reactive aldehydes. Ciba Found. Symp. (67):225-244;1978). Whether as a primary cause of disease or a secondary consequence,such lipid peroxidation is attributed to oxidative stress, which leadsto neural death and this implicated in the progression of a number ofneurodegenerative diseases.

The oxidative stress responsible for such peroxidation is due to animbalance between routine production and detoxification of reactiveoxygen species (“ROS”) that leads to an oxidative attack on the lipidmembrane of cells. The lipid membrane as well as the endoplasmicreticulum and mitochondria of motor neurons are highly enriched inarachidonic acid (a 20-carbon chain polyunsaturated fatty acid (“PUFA”)having 4 sites of cis-unsaturation). Separating each of these 4 sitesare 3 bis-allylic methylene groups. These groups are particularlysusceptible to oxidative damage due to ROS, and to enzymes such ascyclooxygenases, cytochromes and lipoxygenases, as compared to allylicmethylene and methylene groups. Oxidized arachidonic acid is no longerarachidonic acid. Apart from being dysfunctional and leading to furthermembrane damage, oxidation of arachidonic acid reduces the localconcentration of arachidonic acid and must be replaced. Thus, it is adouble hit: a positive bioactive membrane component is converted to atoxic membrane component.

Moreover, once a bis-allylic methylene group in one arachidonic acid isoxidized by a ROS, a cascade of further oxidation of other arachidonicacid groups in the lipid membrane occurs. This is because a single ROSgenerates oxidation of a first arachidonic acid component through a freeradical mechanism which, in turn, can oxidize a neighboring arachidonicacid through the same free radical mechanism which yet again can oxidizeanother neighboring arachidonic acid in a process referred to as lipidchain auto-oxidation. The resulting damage includes a significant numberof oxidized arachidonic acid components in the cell membrane.

Oxidized arachidonic acids negatively affect the fluidity andpermeability of cell membranes in motor neurons. In addition, they canlead to oxidation of membrane proteins as well as being converted into alarge number of highly reactive carbonyl compounds. The latter includereactive species such as acrolein, malonic dialdehyde, glyoxal,methylglyoxal, etc. (Negre-Salvayre A, et al. Brit. J. Pharmacol. 2008;153:6-20). The most prominent products of arachidonic acid oxidation arealpha, beta-unsaturated aldehydes such as 4-hydroxynon-2-enal (4-HNE;formed from n-6 PUFAs like LA or AA), and corresponding ketoaldehydes(Esterfbauer H, et al. Free Rad. Biol. Med. 1991; 11:81-128). As notedabove, these reactive carbonyls cross-link (bio)molecules throughMichael addition or Schiff base formation pathways leading whichcontinues the underlying pathology of the disease.

Disease Progression

When a patient is diagnosed with a specific neurodegenerative disease,the clinician evaluates that patient's rate of disease progression byassessing the patient's loss of functionality in the absence of therapyas described herein. That rate is referred to as the “natural history”of the disease and is typically measured by standardized tests thatmeasure the extent of a patient's functionality over a set period oftime. For example, in the case of ALS, there is a standard test referredto as ALSFRS-R which determines the rate of loss of muscle functionalityover time and this is used to measure the rate of disease progression.This test has 12 components each of which are measured on a 0 (worse) to4 (best) scale. The ability of a drug to attenuate the rate of diseaseprogression evidences its efficacy. Even a modest reduction in the rateof functionality loss is considered significant.

Once therapy with a deuterated arachidonic acid is initiated, thebuildup of this compound in vivo is an incremental process limited byboth physiology as well as the turnover rate of arachidonic acid in thepatient. Unlike conventional drug therapy where the drug has a veryshort half-life in vivo, the mechanism of action of deuteratedarachidonic acid depends on it achieving and maintaining a certainconcentration among all arachidonic acid membranes. It is thereforedesirable to have a long half-life and a high threshold to therapy. Thisis due to the fact that arachidonic acid constitutes both a consumablefood product as well as a product that can be biosynthesized fromlinoleic acid. Taken together, the amount of deuterated arachidonic acidadministered to the patient must account for the amount of arachidonicacid consumed per day (typically about 100 to 300 mg), the amount ofarachidonic acid biogenerated by conversion of linoleic acid, as well asthe amount of arachidonic acid already in the body. This means that theconcentration of deuterated arachidonic acid in the body as a percent oftotal arachidonic acid slowly increases until it reaches a therapeuticlevel.

Given the rapid loss of functionality in patients with neurodegenerativediseases, any dosing regimen employed must address the patient's needfor rapid onset of therapy to preserve as much functionality for thepatient. Hence, any therapy for treating such neurodegenerative diseasesmust be effective as soon as practical and preferably within 45 daysfrom start of therapy, and more preferably within a month or less,thereby retaining as much of the patient's functionality as possible andfurthermore providing for substantial reductions in the rate of diseaseprogression.

Compound Preparation

Deuterated arachidonic acids are known in the art and also can be madeby conventional chemical synthesis. In addition, a variety of deuteratedarachidonic acids, including D2, D4 and D6-arachidonic acids, aredescribed, for example, in Chistyakov, et al., Molecules, 23(12):3331(2018) as well as in U.S. Pat. Nos. 10,052,299 and 10,577,304, all ofwhich are incorporated herein by reference in their entireties. Estersof these deuterated fatty acids are prepared by conventional techniqueswell known in the art.

Methodology—13,13-D2-Arachidonic Acid or Ester Thereof

The methods described herein comprise the administration of deuteratedarachidonic acid or an ester thereof to a patient to treatneurodegenerative diseases mediated by reactive oxygen species.

Treatment with Deuterated-Arachidonic Acids or Esters Thereof

In one embodiment, the deuterated arachidonic acid or esters thereofcomprise D2-arachidonic acid or esters thereof, D4-arachidonic acid oresters thereof, D6-arachidonic acid or esters thereof, or mixturesthereof, each as defined herein. In an embodiment, the deuteratedarachidonic acid or esters thereof comprise D2-arachidonic acid oresters thereof. In an embodiment, the deuterated arachidonic acid oresters thereof comprise D4-arachidonic acid or esters thereof. In anembodiment, the deuterated arachidonic acid or esters thereof compriseD6-arachidonic acid or esters thereof. In an embodiment, the deuteratedarachidonic acid or esters thereof comprise a mixture of D2-arachidonicacid or esters thereof, D4-arachidonic acid or esters thereof, and/orD6-arachidonic acid or esters thereof. In one embodiment, a compositionof deuterated arachidonic acid or ester thereof is employed andcomprises on average at least about 80% of the hydrogen atoms at thebis-allylic sites replaced by deuterium atoms. In one embodiment, thedeuterated arachidonic acid or ester thereof comprises on average atleast about 80% of the hydrogen atoms at the bis-allylic sites replacedby deuterium atoms and no more than about 35% on average of the hydrogenatoms at the mono-allylic sites replaced by deuterium atoms.

In one embodiment, such administration comprises the use of a dosingregimen that includes two dosing components. The first dosing componentcomprises a primer or loading dose of the deuterated arachidonic acid oran ester thereof. The second dosing component comprises a maintenancedose of deuterated arachidonic acid or an ester thereof, wherein theamount of the deuterated arachidonic acid or an ester thereof in saidsecond dosing component is less than that in the first dosing component.

In an embodiment, the loading dose comprises at least about 0.05 gramsof deuterated arachidonic acid or an ester thereof per day. In anembodiment, the loading dose for the deuterated arachidonic acid orester thereof ranges from about 0.05 grams to about 2 grams per day,administered on a periodic basis as described herein. In general, theD4-arachidonic acid or esters thereof will require less of a loadingdose than the D2-arachidonic acid or esters thereof and theD6-arachidonic acid or ester thereof require less of a loading dose thanthe D6-arachidonic acid or esters thereof. Without being limited to anytheory, the ability to reduce the amount of deuterated arachidonic acidor esters thereof with higher levels of deuteration is due to thegreater extent of protection against lipid peroxidation in vivo.accorded by the increased levels of deuteration. Still further, thedosing of about 0.0.5 grams to about 2 grams per day is measured by thetotal amount of deuterated arachidonic acid discounting for impuritiesand the ester portion of the arachidonic acid ester if an ester prodrugis employed. When so employed, the ester group is readily deacylated inthe gastrointestinal track. In embodiments, the loading dose is fromabout 0.05 grams to about 1.5 grams per day. In embodiments, the loadingdose is from about 0.10 grams to about 1.5 grams per day. Inembodiments, the loading dose is from about 0.10 grams to about 1.25grams per day. In embodiments, the loading dose is from about 0.10 gramsto about 1 gram per day. In embodiments, the loading dose is from about0.10 grams to about 0.5 grams per day. The loading dose may be any valueor subrange within the recited ranges, including endpoints.

As to the primer dose, the amount of deuterated arachidonic acid or anester thereof employed is designed to provide rapid onset of therapy.Such therapy is measured by a reduction in the disease progression ofneurodegenerative diseases as described below. In an embodiment, theprimer dose takes into account the various complicating factors, such asthe amount of PUFAs consumed by the patient in a given day as well asthe general turnover rate of lipids (half-life) in the patient'sneurons.

Regarding this last point, the lipid components of neurons are notstatic but, rather, are exchanged over time and have a finite half-lifein the body. In general, only a fraction of the lipids components in thelipids are replaced each day. In the case of neurons, these cells arerich in arachidonic acid. The turnover of arachidonic acid in thesemembranes occurs from a stable pool of lipids comprising arachidonicacid in the spinal fluid. In turn, this stable pool is replaced andreplenished over time by arachidonic acid included in the newly consumedlipids by the patient as part of the patient's diet as well as bybiosynthesis of arachidonic acid from linoleic acid. In embodiments, themaintenance dose of deuterated arachidonic acid or ester thereof istitrated such that the amount of deuterated arachidonic acidadministered matches the rate of secretion from the body.

The choice of a dosing of deuterated arachidonic acid or an esterthereof as described herein allows for the rapid accumulation of asufficient amount of deuterated arachidonic acid in the body to achieveearly onset to therapeutic concentrations in vivo. When so achieved, thedata in the Examples establish that there is a significant reduction inthe rate of disease progression.

In embodiments, the loading dose of the dosing regimen described hereinincludes sufficient amounts of deuterated arachidonic acid that areabsorbed into the patient. Once maximized, the resulting deuteratedarachidonic acid accumulates in the body and reaches a therapeuticconcentration in the patient within about 10 to 45 days after the startof therapy. During this process, deuterated arachidonic acid issystemically absorbed into the cells of the body including neurons. Inembodiments, the loading dose is administered for about 10 to about 50days. In embodiments, the loading dose is administered for about 15 toabout 50 days. In embodiments, the loading dose is administered forabout 20 to about 50 days. In embodiments, the loading dose isadministered for about 10 to about 45 days. In embodiments, the loadingdose is administered for about 15 to about 45 days. In embodiments, theloading dose is administered for about 20 to about 30 days. The lengthof time may be any value or subrange within the recited ranges,including endpoints.

In embodiments, the loading dose is administered at least 5 days perweek. In embodiments, the loading dose is administered at least 7 daysper week. In embodiments, the loading dose is administered at least onceper week. In embodiments, the loading dose is administered at least onceper month.

In embodiments, the maintenance dose of deuterated arachidonic acid oran ester thereof comprises no more than 65% of the loading dose. Inembodiments, the maintenance dose of deuterated arachidonic acid or anester thereof comprises no more than 60% of the loading dose. Inembodiments, the maintenance dose of deuterated arachidonic acid or anester thereof comprises no more than 55% of the loading dose. Inembodiments, the maintenance dose of deuterated arachidonic acid or anester thereof comprises no more than 50% of the loading dose. Inembodiments, the maintenance dose of deuterated arachidonic acid or anester thereof comprises no more than 45% of the loading dose. Inembodiments, the maintenance dose of deuterated arachidonic acid or anester thereof comprises no more than 40% of the loading dose.

In embodiments, the maintenance dose of deuterated arachidonic acid oran ester thereof comprises no more than 35% of the loading dose. Inembodiments, the maintenance dose of deuterated arachidonic acid or anester thereof comprises no more than 30% of the loading dose.

In embodiments, the maintenance dose is administered at least 5 days perweek. In embodiments, the maintenance dose is administered at least 7days per week. In embodiments, the maintenance dose is administered atleast once per week. In embodiments, the maintenance dose isadministered at least once per month.

As is apparent, it is not practical to ascertain the concentration ofdeuterated arachidonic acid in a patient's neurons. This requires thatsuch concentrations be ascertained indirectly by a reporter cell such asa red blood cell, a skin cell, etc. In the case of 13,13-D2-arachidonicacid, at the time a therapeutic result in ascertained, red blood cellsare obtained from the patient, the amount of 13,13-D2-arachidonic acidcontained in said red blood cells based on the total amount ofarachidonic acid present, including 13,13-D2-arachidonic acid ismeasured. When so evaluated, a concentration of at least about 3% andpreferably at least about 5%, and more preferably, at least about 8% of13,13-D2-arachidonic acid when tested at one (1) month after the startof therapy was found to represent a threshold amount required fortherapeutic results in the neurons. When so administered, there is asignificant reduction in the progression rate of the neurodegenerativedisease being treated.

The methods described herein are also based, in part, on the discoverythat the dosing regimen set forth herein provides for rapid uptake oraccumulation of deuterated arachidonic acid in the lipid membrane ofneurons which then stabilizes these membranes against LPO. As a result,there is a substantial reduction in the progression of theneurodegenerative disease. This is believed to be due to the replacementof hydrogen atoms with deuterium atoms in the deuterated arachidonicacid, rendering the deuterated arachidonic acid significantly morestable to ROS than the hydrogen atoms. As above, this stabilitymanifests itself in reducing the cascade of lipid auto-oxidation and,hence, limiting the rate of disease progression.

In the specific instance of ALS, the reduction in the progression ofthis disease can be readily calculated by using the known andestablished rate functional decline measured by the R—ALS FunctionalRating Scale-revised after commencement of drug therapy as compared tothe rate of decline prior to drug therapy (natural history of decline).As the rate of decline is not perceptible on a day-to-day basis, thefunctional decline is typically measured monthly and is evaluated over aperiod of time, such as every 1 to 24 months, such as every 3 months,every 6 months, or annually. The period of time may be any value orsubrange within the recited ranges, including endpoints.

As set forth in the examples below, the rate of functional decline ispredicated on measuring an individual's, or a cohort's, average for thenatural history of disease progression. Next, the individual or cohortaverage for the functional decline is determined at a period of timesuch as at 3, 6 or 12 months after initiation of therapy. The rate ofdecline based on the average of the natural history of the cohort is setas the denominator. The numerator is set as the delta between the rateof the natural history of disease progression and the rate of functionaldecline after a set period of treatment per this invention. Theresulting fraction is the multiplied by 100 to give a percent change.The following exemplifies this analysis.

Cohort A has an average natural history rate of decline in functionalityof 28 annualized for a one (1) year period. Six (6) months afterinitiation of treatment per this invention, Cohort A an annualizedaverage rate of decline in functionality has dropped to 14. Thisprovides a delta of 14 degrees. So, using 14 as the numerator and 28 asthe denominator and then multiplying result by 100, one obtains areduction in the annualized rate of decline of 50 percent.

In general, the methods of this invention provide for an average percentchange in reduction in functionality for a cohort of at least 30% and,more preferably, at least about 35%, or at least about 40%, or at leastabout 45%, or at least about 50%, or at least about 55%, or at leastabout 60%. In embodiments, the change in reduction of functionality ismeasured over a time period, for example 1 month to 24 months, e.g., at3 months, at 6 months, or annually. The rate of decline can be measuredover any time period intermediate between 3 months and 1 year.

As noted above, the dosing regimen also addresses the challenge ofproviding for a dosing regimen that allows for rapid onset totherapeutic concentrations of deuterated arachidonic acid to quicklyreduce the rate of disease progression in the patient so as to minimizethe additional loss of functionality. It is to be understood thatreducing the rate of disease progression correlates to longer periods ofretained functionality in the patient and likely a longer lifespan.Accordingly, the faster one reaches such a reduced rate, the better offit is for the patient.

In one embodiment, the methods described herein address this challengeby employing a dosing regimen which delivers deuterated arachidonic acidin amounts sufficient to provide for a therapeutic amount to theneurons. When so incorporated, the deuterated arachidonic acid reducesthe degree of LPO which, in turn, effectively limits progression of ALSprovided it is administered in appropriate amounts.

Combinations

The therapy provided herein can be combined with other treatments usedwith neurodegenerative diseases provided that such therapy. In oneembodiment, deuterated linoleic acid or an ester thereof (including11,11-D2-linoleic acid ethyl ester) can be used to supplement or replacedeuterated arachidonic acid or an ester thereof in the loading dose orthe maintenance dose provided that replacement is limited to either theloading dose or the replacement dose but not both. This is due to thefact that a portion of 11,11-D2-linoleic acid is bioconverted (e.g.,converted within the body) to 13,13-D2-arachidonic acid. The totalamount so converted is a fraction of the amount of 11,11-D2-linoleicacid or ester thereof administered. This fractional conversion allowsthe clinician to titrate the amount of 13,13-D2-arachidonic aciddownward by administering 11,11-D2-linoleic acid or ester thereof. Thisis particularly the case for the maintenance dose where minimal amountsof 13,13-D2-arachidonic acid may be required as the literaturerecognizes that the amount of biogenerated arachidonic acid is low. See,e.g., Tallima, et al., J. Adv. Res., 11:33-41 (2018). As to11,11-D2-linoleic acid or ester thereof, the term “ester thereof” refersto the same term used with regard to deuterated arachidonic acid oresters thereof.

In another embodiment, a combination therapy can employ a drug thatoperates via an orthogonal mechanism of action relative to inhibition oflipid auto-oxidation. Suitable drugs for use in combination include, butnot limited to, antioxidants such as edaravone, idebenone, mitoquinone,mitoquinol, vitamin C, or vitamin E provided that none of theseanti-oxidants that are directed to inhibiting lipid auto-oxidation,riluzole which preferentially blocks TTX-sensitive sodium channels,conventional pain relief mediations, and the like.

Pharmaceutical Compositions

The specific dosing of deuterated arachidonic acid or an ester thereofis accomplished by any number of the accepted modes of administration.As noted above, the actual amount of the drug used in a daily orperiodic dose per the methods of this invention, i.e., the activeingredient, is described in detail above. The drug can be administeredat least once a day, preferably once or twice or three times a day.

This invention is not limited to any particular composition orpharmaceutical carrier, as such may vary. In general, compounds of thisinvention will be administered as pharmaceutical compositions by any ofa number of known routes of administration. However, orally delivery ispreferred typically using tablets, pills, capsules, and the like. Theparticular form used for oral delivery is not critical but due to thelarge amount of drug to be administered, a daily or periodic unit doseis preferably divided into subunits having a number of tablets, pills,capsules, and the like. In one particularly preferred embodiment, eachsubunit of the daily or periodic unit dose contains about 1 gram of thedrug. So, a daily or periodic unit dose of 9 grams of the drug ispreferably provided as 9 sub-unit doses containing about 1 gram of thedrug. Preferably, the unit dose is taken in one, two or three settingsbut, if patient compliance is enhanced by taking the daily or periodicunit dose over 2 or 3 settings per day, such is also acceptable.

Pharmaceutical dosage forms of a compound as disclosed herein may bemanufactured by any of the methods well-known in the art, such as, byconventional mixing, tableting, encapsulating, and the like. Thecompositions as disclosed herein can include one or more physiologicallyacceptable inactive ingredients that facilitate processing of activemolecules into preparations for pharmaceutical use.

The compositions can comprise the drug in combination with at least onepharmaceutically acceptable excipient. Acceptable excipients arenon-toxic, aid administration, and do not adversely affect thetherapeutic benefit of the claimed compounds. Such excipient may be anysolid, liquid, or semi-solid that is generally available to one of skillin the art.

Solid pharmaceutical excipients include starch, cellulose, talc,glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silicagel, magnesium stearate, sodium stearate, glycerol monostearate, sodiumchloride, dried skim milk and the like. Other suitable pharmaceuticalexcipients and their formulations are described in Remington'sPharmaceutical Sciences, edited by E. W. Martin (Mack PublishingCompany, 18th ed., 1990).

The compositions as disclosed herein may, if desired, be presented in apack or dispenser device each containing a daily or periodic unit dosagecontaining the drug in the required number of subunits. Such a pack ordevice may, for example, comprise metal or plastic foil, such as ablister pack, a vial, or any other type of containment. The pack ordispenser device may be accompanied by instructions for administrationincluding, for example, instructions to take all of the subunitsconstituting the daily or periodic dose contained therein.

The amount of the drug in a formulation can vary depending on the numberof subunits required for the daily or periodic dose of the drug.Typically, the formulation will contain, on a weight percent (wt %)basis, from about 10 to 99 weight percent of the drug based on the totalformulation, with the balance being one or more suitable pharmaceuticalexcipients. Preferably, the compound is present at a level of about 50to 99 weight percent.

In preferred embodiment, the drug is encapsulated inside a capsulewithout the need for any pharmaceutical excipients such as stabilizers,antioxidants, colorants, etc. This minimizes the number of capsulesrequired per day by maximizing the volume of drug in each capsule.

EXAMPLES

This invention is further understood by reference to the followingexamples, which are intended to be purely exemplary of this invention.This invention is not limited in scope by the exemplified embodiments,which are intended as illustrations of single aspects of this inventiononly. Any methods that are functionally equivalent are within the scopeof this invention. Various modifications of this invention in additionto those described herein will become apparent to those skilled in theart from the foregoing description and accompanying figures. Suchmodifications fall within the scope of the appended claims. In theseexamples, the following terms are used herein and have the followingmeanings. If not defined, the abbreviation has its conventional medicalmeaning.

D2-AA = 13,13-D2-Arachidonic Acid AA = Arachidonic Acid ALSFRS-R =Revised ALS Functional Rating Scale CNS = Central Nervous System CSF =Cerebral Spinal Fluid D2-LA = 11,11-D2-Linoleic Acid (aka “drug”) LA =Linoleic Acid LPO = Lipid peroxidation PK = Pharmacokinetics RBC = RedBlood Cells SAE = Serious Adverse Events

Example 1—Determination of AA Concentrations in RBCs and SpinalFluid/Neurons in a Single Patient

This example determines the relative concentration of D2-AA in the CSFand in RBCs in order to determine a correlation between these twoconcentrations. Specifically, a patient was continuously provided with adaily dose of 9 grams of D2-LA ethyl ester (which is 8.64 grams ofactive discounting for impurities and removal of the ethyl ester) overabout a six-month period. Periodic samples of blood and SF were takenand the concentration of both D2-LA and D-2AA in both the RBCs and theSF were measured. In all cases, the D2-AA was obtained by deacylation ofthe ethyl ester of linoleic acid in the gastrointestinal tract followedby conversion of D2-LA in vivo to D2-AA.

TABLE 1 Concentration of Concentration of Ratio of D2-LA to Time D2-LAin CSF D2-AA in CSF D2-AA in CSF 1 month 19.8% 8% 2.5:1The results found in Table 1 show that the concentration of D2-AA in thecerebral spinal fluid is already 8% based on the amount of arachidonicacid+deuterated arachidonic acid.

Next, Table 2 shows that the concentration of D2-LA and D2-AA in theRBCs at 3 months and 6 months for the same patient.

TABLE 2 Concentration of Concentration of Ratio of D2-LA to Time D2-LAin RBCs D2-AA in RBCs D2-AA in RBCs 3 months 34.7% 11.8% 2.9:1 6 months34.5  16.7  2.1:1

Note here that the concentration of D2-AA in RBC's at 3 months is lessthan that at 6 months evidencing the incremental increase in D2-AA overtime. Moreover, there is an apparent change in the ratio of D2-LA toD2-AA at 2.9:1 at 3 months which changes to 2.1:1 at 6 months. In oneembodiment, the ratio of D2-LA to D2-AA in RBCs at 3 and 6 months isrepresented as 2.5:1+/−0.4 which corresponds favorably to that found inTable 1.

Since the amount of D2-AA is increasing over time in an incrementalfashion based on the bioconversion of D2-LA, one can assume a fairlylinear rate of increase. This is shown in FIG. 1, where the solid lineis set by the concentrations of D2-AA at 3 months and 6 months and thenextrapolated back to start of therapy (0 months). The value for theD2-AA in RBC's at 1 month is estimated from this relationship. Theamount shown for 1 month in the CSF is also provided (open circle).

Based on the above, one can see that the data to date suggests that theamount D2-AA at 1 month in RBCs would be about 3 percent as compared to8% for the amount of D2-AA in the SF. Accordingly, this data suggeststhat the concentration the body shunts more of the AA (including D2-AA)into the CSF (and hence the neurons) as compared to RBCs and likelyother reporter cells.

Example 2—Determination of AA Concentrations in RBCs and SpinalFluid/Neurons in a Cohort of 14 Patients

In this example, children suffering from INAD were treated with a dailydose of 3.9 grams of D2-LA ethyl ester followed by 2.9 grams of D2-LAethyl ester. Given the age and weight of these children, such is assumedto be substantially equivalent to a loading dose of from about 7 andabout 12 grams per day for an adult patient for an adult patient and amaintenance dose which is less than the loading dose again for an adultpatient.

This example also determines the concentration of D2-AA in RBCs.Specifically, a cohort of 14 children was provided with a daily dose of3.9 grams of D2-LA ethyl ester for 1 month followed by 2.9 grams ofD2-LA ethyl ester for the remaining six-month period. Blood samples weretaken at 3 months for all but 1 child and at 6 months for all children.The concentration of D2-AA in RBCs was measured. In all cases, the D2-AAwas obtained by deacylation of the ethyl ester of linoleic acid in thegastrointestinal tract followed by bioconversion of D2-LA in vivo toD2-AA.

At 3 months, the average concentration of D2-AA in the RBCs wasdetermined to be 12% (6.8% low and 16.8% high). At 6 months, the averageconcentration of D2-AA in the RBCs was determined to be 16.7% (12.0% lowand 26.1% high). A graph depicting these results is provided as FIG. 2.The line shows a linear relationship of D2-AA accumulation in the body.Included in this graph is the 1-month data for D2-AA in the spinal fluidas found in Example 1.

As can be seen, the graphs in FIGS. 1 and 2 are substantially the same,strongly suggesting that the dosing of D2-LA to the adult patient inExample 1 and to the children in Example 2 maximized the bioconversionof D2-LA to D2-AA. This data further suggests that once maximized, theamounts of D2-AA generated over time are reproducible.

Comparative Example A—the Use of Prodrug of 13,13-Arachidonic Acid

Patients suffering from ALS were treated with D2-LA over a period oftime. The patients were given different dosing amounts of D2-LA and fordifferent dosing periods but did not follow the dosing protocoldescribed in U.S. Ser. No. 17/391,909, which is incorporated herein byreference in its entirety. Some patients were provided 2 grams of11,11-D-2 LA per day as opposed to the loading dose of 9 grams per day.

Functional scores for each of the patients (ALSFRS-R results) at the endof therapy were compared to the natural history scores at the start oftherapy. Based on this comparison, the rate of decline changed from anannualized rate of −14.2+/−4.4 per year pre-treatment to −7.6+/−1.4during treatment or a 46% reduction (p=0.07, paired t-test forwithin-subject change in slope). When calculated, the amount of D2-AA inthe patients' RBCs averaged at about 3% based on the total amount of AAand D2-AA present evidencing that such a concentration provided fortherapeutic results.

As D2-LA acts as a pro-drug of D2-AA, the 3% amount of D2-AA in redblood cells shown to be therapeutic would be independent of whether itis delivered by in vivo conversion of D2-LA or by direct administrationof D2-AA.

Example 3—Benefits of the Dosing Protocol Using D2-LA

This example illustrates the reduction in the rate of diseaseprogression in patients with ALS treated by the dosing methods describedherein. Specifically, a cohort of 3 patients was placed on a dosingregimen consisting of a first dosing component (primer dose) of about 9grams of D2-LA ethyl ester daily for a period of at least 30 days andthen all three patients were transitioned to a second dosing component(maintenance dose) of 5 grams of D2-LA ethyl ester.

The functionality of each of the patients was evaluated periodicallyusing the ALSFRS-R protocol. The patients continued on the dosingregimen for a period of 6 months (patient A) or 1 year (patient B) orfor 9 months (patient C). Patient C died at the end of 9 months and hisdeath was attributed to factors other than ALS cardiomyopathy. Beforeinitiation of therapy, the natural history of each patient in the cohortwas determined and an average annual rate of functional decline wasmeasured at 21.

The annualized progression of the disease, as measured by an averageannual rate of functional decline for all three patients starting at thetime that dosing began and terminating at the end of the dosing regimenand then annualized as described above, was measured as 2.1. Using theformula described above, one obtains the following:(21−2.1)/21×100=90% annualized average reduction in the rate of diseaseprogression.

The specific values for each of the three members of the cohort are asfollows in Table 5:

TABLE 5 NH Rate of Functional Rate Decline Patient Decline DuringTherapy A −16 −3 B −31 −2 C −16 −1.3 NH = Natural History

These results substantiate a very significant rate of reduction in thedisease progression using the dosing regimen as per this invention.These results also substantiate that transitioning patients from aprimer dose to a maintenance dose maintains the beneficial stabilizationin the rate of decline.

In comparison, patients treated with 9 gm of D2-LA per day for about 1month followed by 5 gm of D2-LA per day thereafter evidence about a 90%reduction in the rate of disease progression. Compared to the 46% rateof reduction in the loss of functionality. This establishes that thedosing regimen described herein provides for a significant benefit topatients in their reduction in the rate of disease progression.

Example 4—Survival of Murine Fibroblast Cells in the Presence of Erastin

This example was designed to measure the relative protective activity of13,13-D2-arachidonic acid as compared to 7,7,10,10,13,13-D6-arachidonicacid in protecting murine fibroblasts from lipid peroxidation mediatedcell death. In this example, two different pools of cells were eachseeded in 48-well plates and treated with 50 micromolar of erastin.Cells were incubated with either 13,13-D2-arachidonic acid or7,7,10,10,13,13-D6-arachidonic acid.

Afterwards, cell viability was measured by plate dilution assay todistinguish between cells that are alive and those that are dead on aPetri dish. The results are as follows:

Arachidonic acid employed % Cell Survival 13,13-D2-arachidonic acid 33.27,7,10,10,13,13-D6-arachidonic acid 70.2

These results evidence that 7,7,10,10,13,13-D6-arachidonic acid providesapproximately twice the level of protection against LPO induced celldeath as compared to 13,13-D2-arachidonic acid.

Dosing Based on the Examples

The amount of LA bioconverted to AA is deemed to be in the range of fromabout 5% to about 30% of the LA consumed. The exact conversion ratedepends on factors such as the amount of PUFAs consumed, the amount ofAA present in the body coupled with feedback loops, any rate limitingenzymatic steps, and the underlying metabolism of the patient.Therefore, if 2 grams of D2-LA successfully achieves about a 3.0 percent(a therapeutic level) of D-2AA in red blood cells as per ComparativeExample A above, and if 15% of the D2-LA (approximately half of 5 to 30percent) is converted to D2-AA, then one can deduce that:

A. At a 15% conversion rate, the 2 grams of D2-LA would generate about0.3 grams of D2-AA by bioconversion.

B. At a 30% conversion rate, the 2 grams of D2-LA would generate about0.6 grams of D2-AA by bioconversion.

Still further, Example 4 illustrates that D6-AA is about 2 times moreactive than D2-AA. So, when using D6-AA, one can deduce that it willrequire slightly less than half as much as D2-AA. So, at a low end, the0.3 grams of D2-AA would translate into about 0.15 grams of D6-AA, orperhaps less. As to the loading dose of D4-AA, it will be intermediatebetween that for D2-AA and D6-AA.

Still further, to achieve the benefits of Example 3 of a significantlyreduced rate of loss of functionality, a dose of 9 grams per day ofD2-LA would be required. At a 15% conversion rate, such would translateto 1.45 grams per day of D2-AA. For D6-AA, a reduction by 50% wouldprovide for about 0.75 grams per day.

With the above factors considered, in embodiments, the loading dose ofdeuterated arachidonic acid or ester thereof is expected to range fromabout 0.01 grams to about 2 grams per day. In a preferred embodiment,dosing is from about 0.05 grams to about 1.5 grams per day. Inembodiments, the loading dose is from about 0.10 grams to about 1.5grams per day. In embodiments, the loading dose is from about 0.10 gramsto about 1.25 grams per day. In embodiments, the loading dose is fromabout 0.10 grams to about 1 gram per day. In embodiments, the loadingdose is from about 0.10 grams to about 0.5 grams per day, with preferreddosing ranges of from about 0.1 to about 1.5 grams of deuteratedarachidonic acid. Other preferred ranges are provided above.

In embodiments, the maintenance dose of deuterated arachidonic acid oran ester thereof comprises no more than about 65% of the loading dose.In one embodiment, the maintenance dose of deuterated arachidonic acidor an ester thereof comprises no more than 55% of the loading dose. Inone embodiment, the maintenance dose of deuterated arachidonic acid oran ester thereof is calibrated to be an amount of deuterated arachidonicacid or an ester thereof sufficient to replace the amount of deuteratedarachidonic acid eliminated from the body.

The invention claimed is:
 1. A method for reducing disease progressionof a neurodegenerative disease treatable with a deuterated arachidonicacid in an adult patient, the method comprising: administering adeuterated arachidonic acid or an ester thereof to the patient with adosing regimen that comprises a primer dose and a maintenance dose,thereby reducing said disease progression in said patient, wherein: a)said primer dose comprises periodic administration of a deuteratedarachidonic acid or an ester thereof, wherein said primer dose iscontinued for about 30 days to about 45 days to rapidly achieve atherapeutic concentration of said deuterated arachidonic acid in vivo;and b) subsequent to the completion of the primer dose, periodicallyadministering said maintenance dose of no more than about 65% of theprimer dose of deuterated arachidonic acid or an ester thereof per daythereof to maintain said therapeutic concentration of said deuteratedarachidonic acid in vivo, such that the rate of disease progression isreduced, wherein the neurodegenerative disease is mediated at least inpart by lipid peroxidation of polyunsaturated fatty acids in neurons ofthe patient.
 2. The method of claim 1, wherein said disease isamyotrophic lateral sclerosis, Huntington's Disease, progressivesupernuclear palsy (PSP), APO-e4 Alzheimer's Disease, corticobasaldisorder (CBD), frontotemporal dementia (FTD), nonfluent variant primaryprogressive aphasia (nfvPPA), other tauopathies, or late onsetTay-Sachs.
 3. The method of claim 1 or 2, wherein said periodicadministration of the primer dose comprises administration of at leastabout 0.05 grams of deuterated arachidonic acid or an ester thereof perday for at least 5 days per week.
 4. The method of claim 1 or 2, whereinsaid deuterated arachidonic acid or an ester thereof comprises a C1-C6alkyl ester of a deuterated arachidonic acid.
 5. The method of any oneof claims 1 to 4, wherein the maintenance dose comprises no more than55% of the primer dose.
 6. The method of claim 5, wherein themaintenance dose comprises no more than 35% of the primer dose and isadministered at least once a week.
 7. The method of claim 6, wherein themaintenance dose is administered at least once a month.
 8. The method ofany one of claims 1 to 7, which further comprises restricting thepatient's consumption of excessive dietary polyunsaturated fatty acidsduring administration of said primer and said maintenance doses.
 9. Themethod of any one of claims 1 to 8, wherein said primer dose and/or saidmaintenance dose is provided in 1, 2 or 3 administrations during asingle day.
 10. The method of any one of claims 1 to 9, wherein saidneurodegenerative disease is amyotrophic lateral sclerosis, Huntington'sDisease, progressive supernuclear palsy (PSP), or APO-e4 Alzheimer'sDisease.
 11. The method of claim 10, wherein said neurodegenerativedisease is APO e-4 variant of Alzheimer's Disease.
 12. The method ofclaim 10, wherein said neurodegenerative disease is PSP.
 13. The methodof claim 10, wherein said neurodegenerative disease is Huntington'sDisease.
 14. The method of claim 10, wherein said neurodegenerativedisease is amyotrophic lateral sclerosis.
 15. A kit of parts comprisinga set of capsules each comprising a partial loading dose of a deuteratedarachidonic acid or an ester thereof, such that two or more of saidcapsules comprise a complete loading dose per day.
 16. A kit of partscomprising a set of capsules each comprising a partial loading dose of adeuterated arachidonic acid or an ester thereof, such that nine of saidcapsules comprise a complete loading dose per day.
 17. A kit of partscomprising a set of capsules each comprising a partial maintenance doseof a deuterated arachidonic acid or an ester thereof, such that two ormore of said capsules comprise a complete maintenance dose per day. 18.A kit of parts comprising a set of capsules each comprising a partialmaintenance dose of a deuterated arachidonic acid or an ester thereof,such that five of said capsules comprise a complete maintenance dose perday.